With the rapid development of Internet and the popularity of large-screen multifunctional mobile phones, there has been a large number of mobile data and multimedia services and a variety of high bandwidth multimedia services, such as video conferencing, TV broadcasting, video on demand, advertising, online education and interactive games, which not only meet the growing service requirements of mobile users, but also bring a new service growth point to mobile operators. These mobile data and multimedia services require multiple users to simultaneously receive same data, and compared with common data services, have characteristics such as a large amount of data, long duration, and latency-sensitive.
In order to effectively use the mobile network resources, the 3rd Generation Partnership Project (3GPP) proposes a MBMS service, which is a technology of transmitting data from one data source to multiple targets, thus achieving sharing the network (including a core network and an access network) resources and improving the utilization of the network resources (especially the air interface resources). The MBMS defined by 3GPP can not only achieve plain text, low-rate messages type multicast and broadcast, but also can achieve high-speed multimedia services broadcast and multicast, and provide a variety of abundant video, audio and multimedia services, which undoubtedly conforms to the trend of the development of future mobile data and provides better business prospects for the development of 3 G.
The characteristics of MBMS services are a large amount of data of the services, a long period during which the terminal receives data, and a constant average data rate. The above characteristics determine both the scheduling and control signaling configuration of the MBMS services are semi-static, i.e., both the scheduling information and the control signaling information of the MBMS services are kept “long-term” unchanged, and thus a periodic system side of each Multicast Control Channel (MCCH) information transmits unchanged information (It is always transmitted, because there may be a new user to access at any time). Thus, a terminal, which has received the MCCH information, does not need to receive unchanged MCCH information each time, which will cause the terminal to waste power, because the MCCH information has a large amount of information, and the process of receiving and parsing of the MCCH information will consume relatively more power. Therefore, it is proposed that one MCCH information update indication information (also referred to MBMS notification messages by some companies, and the present invention takes MBMS notification message as an example) is added, which use a small amount of information to describe whether the MCCH information is changed. The terminal which has access to the network just needs to monitor a small amount of information, and determines whether to receive the MCCH information according to the MBMS notification message.
In Long Term Evolution (LTE), the MBMS services can be transmitted by means of a mixed carrier, which means Unicast service (Unicast) and Multicast Service (MBMS service) are transmitted on the same carrier by means of time division multiplexing. The smallest unit used by time division multiplexing is one sub-frame. At present, the LTE defines that a two-stage method is used to configure radio frames and sub-frames carrying MBMS services.
At present, in the LTE, first one or two Orthogonal Frequency Division Multiplexing (OFDM) symbols in the MBSFN sub-frames are used to transmit the information of Unicast services, which is also known as Physical Downlink Control Channel (PDCCH), and the remaining resources in the sub-frames are used to transmit MBMS services or other services.
While it has been determined to introduce the MBMS notification message and to use PDCCH and it has been determined to use RNTIs at the present time, it has not been determined where RNTIs should be in the PDCCH and what kind of RNTI should be used. In addition, at present, there are a variety of sub-frames with different uses in the LTE, such as unicast sub-frames which are mainly used to transmit unicast traffic data, sub-frames mainly used to transmit paging messages, and MBSFN sub-frames which are mainly used to carry MBMS services and can also be used to carry data transmitted from the base station to the relay, therefore, it is more reasonable to select the PDCCH of these sub-frames.